The present invention relates to an improved electronic calculator characterized in that besides the calculation functions of conventional electronic calculators, it is very convenient for input of data and instructions, definitely greatly increasing the efficiency of the electronic calculator and making the application of electronic calculator more widespread and convenient.
The existing electronic calculators typically have an arrangement of a front panel with a data display screen on the top of the input keys. The drawbacks of such arrangement reside in that the data display screen is spaced from the keys for a certain distance, additionally, the keys are positioned below the display screen, making the full utilization of human vision in unfavorable situation. In such situation when one is using the electronic calculator, whenever a number or operation instruction is being input, he has to move his visual line from the display screen to the key to be pressed. When one has finished the action of pressing a key, he has to move his visual line again from the position of the key to the display screen to view the result of the operation for determining the correctness of his operation. Thus, each time for one to perform an operation, he has to move his visual line up and down twice. In practice, there will be large amount of data required to be computed and processed, especially for technical and financial personnel, the input amount of data and operation instructions is undoubtedly large. And the number of up and down movements of the human visual line is twice that of the inputs. Such frequent up and down movements of the human visual line very likely cause one""s eyes to be tired, even resulting in dizziness, this makes financial personnel subject to error making. On the other hand, it severely limits the speed of the use of the electronic calculators, reducing the efficiency of the use of the electronic calculators. It is well known that electronic calculators have the advantages of high operation speed and calculation accuracy. But many people have already felt that the functions of the electronic calculators are limited due to the inconvenience of their input. which in turn limits the use of electronic calculators severely. Due to the above mentioned reasons, most of the financial personnels are still using the old calculation tool, i.e., abacus, to perform calculation, and rarely using such advanced calculation tool as electronic calculator, this is a backward phenomenon fallen behind the development of science. In fact, a lot of people have endeavored to solve the hard problem of difficulty of the input of electronic calculators. Some of them have tried to do so by increasing the size of the keys, some of them by decreasing the number of keys, and yet some of them by reducing the functions of the electronic calculator. However, all those ways are less effective, without substantial effect. In fact, this problem has not been solved up-to-date.
It is therefore an object of the present invention to provide a new type of easy-to-use electronic calculator which can conveniently solve the problem of difficulty of data and operation instructions input of electronic calculator. This will provide an ideal and popular xe2x80x9cnew type of easy-to-use electronic calculatorxe2x80x9d.
The present invention is based on the long-time thorough observation and investigation of the characteristics of Herman vision, which reveals that human vision has the following characteristics, i.e., the residuary light area above the human visual line is greater than the residuary light area below the visual line. In accordance with this characteristic, the input keys of the electronic calculator originally positioned below the display screen are moved to the upper, upper right and right sides adjacent to the display screen, some of the infrequently used keys may still be arranged at positions easy-to-operate immediately below the display screen, as shown in FIGS. 1, 2, and 3. Thus, one only needs to always keep his visual line on the display screen while performing calculation operation, but with the residuary sight of his eyes to monitor the input by pressing keys. This allows the convenient input by pressing keys without the multiple to-and-fro movements of the human visual line, of course, this may reduce the burden of human eyes, as well as in crease the speed and efficiency of the use of the electronic calculator and improve the accuracy of operation.
It is discovered by observation that a number is input into the electronic calculator at the last digit. From this feature, one has only to watch and determine whether the last digit of an input number on the display screen is correct to determine the correctness of each operation. Thus, when one is performing calculation operation on the electronic calculator, he has only to concentrate his attention on the last digit of the display screen. Thereby, the last digit on the display screen may be orderly arranged with the ten frequently used numeric keys 0 through 9, that is, the last digit on the display screen is arranged in an area of suitable size, concentratively with the ten numeric input keys, this area may be simultaneously within a visual field without or with little movement of the human visual line. The input keys of an electronic calculator can be appropriately arranged in partitioned areas according to their functions, and high light this small area with suitable indicative pattern, making it more eye-catching.
In the various arrangement schemes mentioned above; the last numeric digit on the display screen can be enlarged, for example, to occupy the position of two digits. This arrangement will make the last digit more eye-catching, and the input performance more convenient.